I have seen this before and it is very cool. I posted this topic under aquaponics because it is a very innovative field. People have many ideas to get water to move how and when they want it.
I have a 5000 sq ft garden with no running water or electricity. I have to walking to the local well right now to get water. I plan on building a cob shed there with one or two IBC's to catch water. From there I want the water to slowly drip from the IBC's into a system that would send water to various drip irrigation manifolds to send water a few times a day to certain zones in the garden. I am just trying to figure out how to do this. With this cup idea on the bell siphon I wonder how slow the water flow can be.
I was thinking something that gets full and at one point dumps itself because of the weight. Kind of like this
http://www.mastergardenproducts.com/deerchaserstanding.jpg but maybe different.